Refers to https://docs.oasis-open.org/virtio/virtio/v1.2/cs01/virtio-v1.2-cs01.html#x1-2230004
A driver SHOULD negotiate VIRTIO_NET_F_MAC if the device offers it.
If the driver negotiates the VIRTIO_NET_F_MAC feature, the driver MUST
set the physical address of the NIC to mac. Otherwise, it SHOULD use a
locally-administered MAC address.
Signed-off-by: liqinhui <liqinhui@xiaomi.com>